Axolotls are classified as amphibians, not reptiles. They belong to the class Amphibia, which encompasses a diverse group of animals including frogs, toads, and salamanders.
One of the most distinguishing characteristics of amphibians is their dual life cycle, which typically includes a larval stage that is aquatic and a mature stage that can be terrestrial or aquatic. Axolotls are unique in that they retain their larval features into adulthood, a phenomenon known as neoteny. This means they keep their gills and remain in water throughout their lives.
In contrast, reptiles are a separate class of animals that do not undergo such a life cycle. Reptiles, like snakes and lizards, typically have dry skin covered in scales and lay eggs with a hard shell.
Therefore, due to their biological characteristics and life cycle, axolotls are most accurately categorized as amphibians.